This study involves both hardware and clinical application. The hardware objective is the development of an instrument which will make feasible the analysis of "texture". Many of the most important potential applications of computer pattern recognition in clinical medicine have not yet been successfully carried out on a feasible basis because of the following fundamental difficulty. These applications require an evaluation of the "texture" of the objects in the picture as a basic ingredient to successful pattern recognition. Texture analysis by a digital computer involves a type of computing that is presently extremely time consuming and therefore very expensive. This is because texture analysis involves the comparison of each point (or a selected collection of points) with every other point (or every point in some neighboring region around the selected points) of the picture. Since a digital computer can work with only one point at a time (or at most, only the few points that can be packed into a single computer word) the number of instructions that must be executed is extremely large. Our objective is to solve this problem by building a high-speed special-purpose computer, called the TEXAC, that can perform texture operations within fractions of a second. The significance of the TEXAC is that it will enable texture operations to be performed on a feasible basis for the first time. We believe this device will enable vital breakthroughs in many extremely important areas of automatic picture pattern recognition in clinical medicine, on an economical and technically feasible basis. Our clinical objectives are to carry out several projects in picture pattern recognition in clinical medicine. In each of them we collaborate with a clinical physician who is faced with the practical problems of everyday patient care. The clinical projects are the analysis of (1) white blood cells, (2) Pananicolaou smear, (3) lung X-rays, (4) echocardiographs, and (5) electron micrographs.